If they try and open in your town, attend every zoning board meeting.
Take pictures at other Big Box locations and show them at the meeting. Force
them to provide environmental impact statements, traffic studies and urine
samples.

If they do open in your town, buy stuff from them, open it, then return
it. Complain loudly in front of everyone about the poor quality.
Get their highly compensated employees really frustrated so they are in a foul
mood for the next customer.

If there are local laws about item pricing contact the consumer affairs department of your
town or county and file a complaint (Big Box stores almost never price items). Check local
zoning codes and complain if the store violates sign, lighting, trash or other regulations.

Fill up carts with merchandise, then leave it in the aisle. Even
better, bring the cart to the checkout, and after they ring it all up say
"Oops, forgot my money in the car. Be right back!" Leave and don't come
back.

Ask an employee for bogus products - "Do you stock fallopian tubes?"
"Where are the butt plugs?" If they don't know, tell them to ask the manager,
then leave while they're checking.

Do you have more ideas?
Let us know
and maybe we'll add them to this page. By the way, we're just kidding
about all those ideas....remember this is just a parody site. Doing bad things to the wonderful owners of
the Big Box would be really, really mean.